It's probably debconf using the Qt interface which creates this warning. As debconf is using libqt-perl I assume the warning originates from there.
** Changed in: Ubuntu Sourcepackagename: None => libqt-perl -- Error message when using apt-get (appears to be non-harmful) https://launchpad.net/bugs/66856 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
